Furnace Repair or Replace? A Brockville & Kingston Homeowner's Decision Guide
Last updated: August 2026
Repair your furnace if it's under 15 years old, has been running reliably, and the fix is a minor part like an ignitor or sensor. Replace it if it's past 15 years old, repairs are stacking up, or — regardless of age — if the heat exchanger is cracked, which is a carbon monoxide safety risk and not a repair decision. Furnace replacement in Brockville and Kingston typically costs $4,000–$7,500 installed.
How old is too old for a furnace?
A well-maintained gas furnace typically lasts 15–20 years. Under 10 years old, repair almost always makes more sense than replacement; past 15 years, internal components — especially the heat exchanger — become more failure-prone. Annual maintenance, filter changes, and installation quality all extend a furnace's usable lifespan.
What's the one sign that means replace, no matter the age?
A cracked heat exchanger. It's the single failure that overrides the age-and-cost math, because a cracked exchanger can leak carbon monoxide into the home. Ontario's Hawkins-Gignac Act requires working carbon monoxide alarms in any home with fuel-burning appliances — this law exists specifically because of a cracked-heat-exchanger CO poisoning case.
What other warning signs point toward repair vs. replace?
Rust or corrosion on the cabinet or flue, short-cycling (turning on and off rapidly), and a yellow or flickering pilot flame all point toward replacement on an aging unit — but on a newer furnace, the same symptoms are often a straightforward repair.
| Sign | Furnace under 10 years | Furnace 10–15 years | Furnace 15+ years |
|---|---|---|---|
| Minor part failure (ignitor, sensor, relay) | Repair | Repair | Repair, unless repeat failures |
| Rust/corrosion on cabinet | Repair, monitor | Get inspected | Lean replace |
| Short-cycling | Repair | Repair or replace depending on cause | Lean replace |
| Cracked heat exchanger | Replace | Replace | Replace |
| Yellow/flickering pilot | Inspect immediately | Inspect immediately | Inspect immediately |
How do I do the cost math myself?
If a repair quote comes in at more than roughly half the cost of a full replacement, replacement is usually the better long-term value — especially on a furnace already past 12–15 years old. Factor in that a new furnace also brings efficiency gains (lower monthly bills) that an aging, repaired unit won't deliver.
If you're replacing anyway, it's worth comparing a straight furnace swap against a heat pump or hybrid system before deciding. A heat pump may qualify for Ontario rebates that a furnace doesn't.
What does furnace replacement cost in Brockville and Kingston?
Furnace or boiler installation/replacement typically runs $4,000–$7,500 per system in this region. Price depends on furnace size (BTU output), efficiency tier, and whether ductwork needs modification.
Before hiring anyone, verify their TSSA license. See the complete HVAC buyer's guide for more.